Recent activity

The geomagnetic field was inactive to quiet on March 8. Solar wind speed
ranged between 318 and 378 (all day average 342) km/sec. Solar wind temperature
and the total field increase of the interpalnetary magnetic field early on March
9 indicate that a weak stream from CH215 may have arrived.

Solar flux measured at 20h UTC on 2.8 GHz was 72.4. The planetary A index
was 4 (STAR Ap - based on the mean of three hour interval ap
indices: 4.0).
Three hour interval K indices: 21001112 (planetary), 22011110 (Boulder).

The background x-ray flux is below the class A1 level.

At midnight the visible solar disk was spotless. The solar flare activity
level was very low. No C class events were recorded during the day.

Coronal mass ejections (CMEs)

March 6-8:
No obviously fully or partly Earth directed CMEs were observed in limited LASCO
imagery. The filament
eruption in region 10856 on March 7 may have been associated with a small CME
with potentially Earth directed extensions.

Coronal holes

A recurrent trans equatorial coronal hole (CH215) appears to have become larger over the last solar rotation and
was in an Earth facing position on
March 5-7.

Processed SOHO/EIT 284 image at 01:20 UTC on February 28. The
darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is
expected to be quiet to unsettled on March 9-11 due to effects from CH215.

Coronal holes (1)

Coronal mass ejections (2)

M and X class flares (3)

1) Effects from a coronal hole could reach Earth
within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Propagation

Long distance low and medium
frequency (below 2 MHz) propagation
along east-west paths over high and upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic
propagation conditions are normally monitored every night on 1470 kHz. Dominant
stations tonight: WWNN Pompano Beach FL and Radio Vibración (Venezuela).
Propagation was best to the southeastern part of the USA, the Caribbean and
northern South America.

Data for all numbered solar regions according to the Solar Region
Summary provided by NOAA/SEC. Comments are my own, as is the
STAR spot count (spots observed at or inside a few hours before
midnight) and data for regions not numbered by SEC or where SEC has observed no spots.
SEC active region numbers in the table below and in the active region
map above are the historic SEC/USAF numbers.

Active region

Date numbered

SEC
spot
count

STAR
spot
count

Location at midnight

Area

Classification

Comment

10856

2006.02.27

1

S08W50

0010

AXX

spotless

10857

2006.03.05

3

N09E00

0020

AXX

spotless

S629

2006.03.06

S15W10

plage

Total spot count:

4

0

SSN:

24

0

Monthly solar cycle data

Month

Average solar
flux at Earth

International sunspot number

Smoothed sunspot number

2000.04

184.2

125.5

120.8
cycle 23 sunspot max.

2000.07

202.3

170.1

119.8

2001.12

235.1

132.2

114.6 (-0.9)

2005.01

102.2

31.3

34.6
(-0.6)

2005.02

97.2

29.2

33.9
(-0.7)

2005.03

89.9

24.5

33.5
(-0.4)

2005.04

86.0

24.2

31.6
(-1.9)

2005.05

99.3

42.7

28.9 (-2.7)

2005.06

93.7

39.3

28.8 (-0.1)

2005.07

96.4

40.1

29.1 (+0.3)

2005.08

90.5

36.4

27.4 (-1.7)

2005.09

91.1

21.9

(25.6
predicted, -1.8)

2005.10

77.0

8.5

(23.8
predicted, -1.8)

2005.11

86.3

18.0

(21.4
predicted, -2.4)

2005.12

90.7

41.2

(18.5
predicted, -2.9)

2006.01

83.4

15.4

(15.4
predicted, -3.1)

2006.02

76.5

4.7

(12.3
predicted, -3.1)

2006.03

74.7 (1)

3.8 (2)

(10.1
predicted, -2.2)

1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC)
sunspot number. The official international sunspot number is typically
30-50% lower.

This report has been prepared by Jan
Alvestad. It is based partly on my own observations and analysis, and
partly on data from some of these solar data sources.
All time references are to the UTC day. Comments and suggestions are always welcome.